A substrate processing apparatus for processing a substrate such as a semiconductor wafer or the like includes, e.g., a FOUP that is a transfer container or a plurality of modules used for processing or transferring a substrate. The substrate is transferred therebetween by a transfer arm.
In such a substrate processing apparatus, coordinates (X, Y, Z) of a position where the transfer arm enters a module need to be acquired to transfer the substrate to a proper position in the module. To that end, an apparatus maker, for example, performs teaching for acquiring the coordinates of the entering position of the transfer arm based on reference coordinates which are acquired when the apparatus is manufactured.
When the apparatus is assembled by a user, an assembly error may occur and the coordinates (X, Y, Z) of the entering position of the transfer arm may be different from coordinates provided by the maker. Therefore, the user also needs to perform the teaching.
In order to automatically perform the teaching, the position of the transfer arm needs to be detected in advance. In other words, it is required to obtain corresponding relation between a position in an actual transfer space and a position in a coordinate system managed by a driving system of the transfer arm.
Japanese Patent Application Publication No. 2006-185960 (see paragraphs [0026] to [0032] and FIG. 3) discloses a technique for detecting a vertical position of a jig by using a mapping sensor provided at a transfer arm. In this technique, a horizontal position of the jig cannot be automatically obtained, so that the horizontal position of the jig is detected by manually moving the transfer arm. This requires skills and leads to increase in the number of processes.
Japanese Patent Application Publication No. 2005-260176 (see paragraphs [0067], [0083], [0087], [0090] and the like) discloses a technique for acquiring information on a vertical position of a target by emitting laser beam to a target jig and then acquiring information on a radial position of the target jig by using a non-contact sensor (mapping sensor). However, in this technique, the target jig needs to be located at a transfer position by an operator and, thus, the teaching cannot be automatically performed. Further, in this technique, although the information on the vertical position and the radial position of the target position can be acquired, XY coordinate in the horizontal plane cannot be detected.